Diseases & Conditions A - Z
powered by Talix

Brain Health Overview

The brain is the most important and most complex part of the body. It controls almost all body processes including:

  • heartbeat
  • breathing
  • digestion
  • muscle movement
  • speech
  • all five senses

The brain is also responsible for memory, emotion, behavior, and reasoning. The health of the brain is vital to nearly everything we do.

How Is the Brain Structured?

The brain sits inside the skull, which protects it from injury. Between the skull and the brain are three layers of tissue called the meninges. They also help protect the brain and spinal cord.

The brain is an extremely complex structure. Each part of the brain serves its own specific function and works together with other parts of the brain to perform even more complex functions. The brain can be described in four main parts.

Brain Stem

The brain stem is at the base of the brain and connects the cerebrum directly to the spinal cord. It controls many involuntary but necessary processes in the body, such as breathing, heart rate, swallowing, and blood pressure. The brain stem relays messages from the brain to other parts of the body. We cannot survive without it.


The cerebellum is located at the back of the brain. It’s responsible for movement, posture, and balance. Many of the motor functions that come from the cerebrum have to pass through the cerebellum before the body carries them out.

Limbic System

The limbic system is a collection of several structures at the center of the brain. These structures control emotion and memory.


The cerebrum forms the major portion of the brain. It’s divided into left and right halves, called hemispheres. The left hemisphere controls the right side of the body, and the right hemisphere controls the left side of the body. Each hemisphere is subdivided into four lobes:

  • The frontal lobes are responsible for logical reasoning, concentration, intelligence, emotions, and problem solving
  • The parietal lobes are important for spatial orientation, integrating sensory information, and motor function
  • The occipital lobes are responsible for vision, including how we process colors and shapes
  • The temporal lobes are responsible for hearing and speech. They help us to remember and understand language

What Can Go Wrong With the Brain?

One unfortunate consequence of the brain's complexity is that so many different things can go wrong with it. The National Institute of Neurological Disorders and Stroke (NINDS), for example, researches over 600 different neurologic diseases. There are several more common types of brain disorder.

Brain Trauma

Brain trauma may be caused by a number of things, including:

  • motor vehicle crashes
  • sports accidents
  • falls
  • firearms
  • being struck by an object

It usually happens suddenly and requires immediate treatment. A concussion, for example, is a sharp blow to the head that causes the brain to collide against the inside of the skull. Symptoms usually last for a few days and up to two week and can include:

  • drowsiness
  • severe headache
  • confusion
  • memory loss
  • nausea

Anyone who suffers a blow to the head needs to seek medical attention, even if they feel fine. There could be bleeding in the brain that may be fatal if not detected right away. More severe cases of traumatic brain injuries can lead to an extended period of unconsciousness (coma), or even death.


A brain aneurysm is a bulge in the wall of an artery in the brain. Common symptoms include:

  • pain behind the eyes
  • numbness or weakness in the face
  • double or blurry vision

If untreated, an aneurysm can rupture and cause a sudden, extremely severe headache or death.  A ruptured aneurysm is a severe medical emergency.


A stroke is an interruption of blood flow to part of the brain caused by bleeding in the brain or by a blood clot clogging an artery. Stroke symptoms come on suddenly and may include:

  • confusion
  • trouble speaking
  • dizziness
  • headache
  • numbness or weakness on one side of the body

If you experience symptoms of a stroke, it’s essential to seek medical attention as soon as possible. Prompt treatment can save areas of brain from permanent damage.

Degenerative Brain Diseases

Degenerative brain diseases cause progressive damage to the parts of the brain that control cognition, emotion, and mobility. The damage tends to accumulate and increase over a long period of time.

The most common form of degenerative brain disease is dementia. People with dementia undergo a gradual loss of intellectual and cognitive abilities over time, but this typically doesn’t start until after age 60. The initial signs and symptoms of dementia may be subtle but can progress from lapses in memory to include:

  • trouble dealing with numbers and directions
  • difficulty speaking and understanding language
  • personality changes
  • an inability to perform even basic tasks

Alzheimer’s disease is the most common form of dementia. Despite this, the exact cause is still unknown. Genetics is thought to play a role. Alzheimer’s disease and other types of dementia typically occur in older individuals. The risk increases as you age.

If you are concerned that a member of your family is beginning to show signs of dementia, it’s important to talk to a doctor. Several basic tests can help your doctor determine whether any of the symptoms are reversible and how to support the patient as they begin to deal with any new diagnosis.


Epilepsy is a disease that causes abnormal electrical discharges in the brain. The main symptom of epilepsy is repeated seizures, which are episodes of disturbed brain function. A seizure can manifest as one or more of the following symptoms:

  • temporarily altered perception of sounds, smells, sights, and tastes
  • uncontrollable jerking of the muscles
  • staring or repeated motions
  • complete loss of consciousness

The brain can also be affected by tumors, bacterial and viral infections, genetic diseases, metabolic conditions, and a number of other developmental disorders and conditions.

How Can You Keep Your Brain Healthy?

Like other parts of the body, your brain may lose some agility as you get older. Some brain conditions, like Alzheimer’s disease, may not be preventable. There are many things you can do now to help keep your brain healthier as you age. You can take certain precautions to reduce the risk of certain types of dementia or brain trauma, or delay the onset of dementia.

The Alzheimer’s Association and the Brain Foundation offer the following tips on keeping your brain healthy.

  • Stay physically active and exercise to promote blood flow to the brain.
  • Engage in mentally stimulating activities throughout life, like doing puzzles, memory games, or learning a new language.
  • Reduce stress and depression. Regular exercise can help with this.
  • Eat a healthy, low-fat, low-cholesterol diet that is rich in dark vegetables, fruits, and antioxidants such as vitamins C and E. Omega-3 fatty acids, commonly found in certain fish and nuts, may also help lower your risk of dementia.
  • Wear a helmet when riding a bicycle or motorcycle to prevent a brain injury if you fall or get into an accident.
  • Always wear a seatbelt when driving.
  • Treat any head injury seriously.
  • Get adequate sleep.
  • Do not smoke.
  • Get regular checkups from your doctor.

Additionally, the National Stroke Association (NSA) has published Stroke Prevention Guidelines to help reducing your risk of stroke. The guidelines include the following recommendations.

  • Know your blood pressure. High blood pressure is a major risk factor for stroke. Talk with a doctor about what to do if your blood pressure is high
  • Know your cholesterol levels. High cholesterol levels in the blood can clog the arteries. Speak with your doctor about getting your cholesterol checked.
  • Lose weight if you are overweight. Eating a healthy diet and maintaining a healthy weight are important for a functioning circulatory system.
  • Stop smoking. Smoking can damage blood vessels and raise your blood pressure.
  • Limit your alcohol intake. If you must drink, do it in moderation.

Content licensed from:

Written by: Healthline Editorial Team & Jacquelyn Cafasso
Medically reviewed on: Sep 04, 2014: Brenda B. Spriggs, MD, MPH, MBA

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
Symptom Search
Enter your symptoms in our Symptom Checker to find out possible causes of your symptoms. Go.
Drug Interaction Checker
Enter any list of prescription drugs and see how they interact with each other and with other substances. Go.
Pill Identifier
Enter its color and shape information, and this tool helps you identify it. Go.
Drugs A-Z
Find information on drug interactions, side effects, and more. Go.